Threaded sheet metal plug



Oct. 30, 1945. I w c GROSSER 2,387,990

I THREADED SHEET METAL PLUG Filed Sept. 8, 1941 Arraexveys.

mitted thereto for screwing or unscrewing the p s- Moreover, it is an object of the'pres'ent invention to provide athreaded sheet metal plug having a notched, curled bead at the periphery of the flange thereof, which notches are slightly undercut, whereby any available toolsuch as a bar, screw driver, chisel, or the like may be readily engaged With the plug for screwing or un-' screwing the same.

Moreover, it is an object of the present inven-' tion to provide a threaded sheet metal plug having a flanged sheet metal head, which has sufiicient springiness to uniformly distribute pressure of the plug head on a liquid sealing gasket so as to .easily seal the samein liquid sealing relation regardless ofthe type of'gasket used without requiring an extreme force to beapplied to the plug for tightening thesame,

Moreoven-it is anobject of the present invention to provide a threaded sheet metal plug having characteristics described in one or more of the preceding objects, ,and which isadapted, to be eceived in any One of a number of types of threaded container bung openings provided with standard pipe threads.

Also it is an object ofthe present invention to provide a threaded sheet metalplughaving characteristics described in one or more of the preceding objects, which when received inany one or a number of 'difl'erent types of threaded bung openings, may beprovided with a, lead and wire seal, or'with a tamper-proofsealing cap.

And finally, it is an object of the present invention to provide a threaded sheet metal closure plug and the like having characteristics described in the preceding objects, which accomplishes the stated desiderata, which may be manufactured cheaply, and which may be readily, easily and effectively used. v

These and other objects may be obtained by the elements, parts, combinations and constructions constituting the present invention, a preferred embodiment of which is shown in the accompanying drawings, and is hereinafter claimed I and'des cribed in detaiL which may be stated in general terms as including ina sheet metal plug structure, a' closure wall provided with an integral tubular neck orannular projection,v the neck terminating in an outturned annular flange,

the neck between the closure wall and flange being cold rolled, swa'ged, deformed, worked, and.

displaced to provide a standard V -sided pipe thread formation therein, 'the outturned flange terminating in an annular"inwardlycurled' bead for reinforcing and stiffening the plug, the bead outer end of the plug and bung-opening"- In the accompanying drawing 1 a Figure 1' is an axial section illustrating the improved plug assembled in a container bung opening taken on the line 1-]; Fig. 2; I Fig. 2 isa plan view with parts broken away and in section, taken on the line 2-4, Fig. 1';-

' Fig. 3-is a section taken on the line 3 3,\Flg. l,

with the seal cap removed, and witha portion of a plug turning wrench illustrated in dot-dash lines; V

Figl 4 is a side elevation partly in section of the head of a wrench adapted for turning plugs ,of the type illustrated in Figures 1 to 3;

Fig. 5 is a fragmentary bottom view showing the tooth conformation of the Wrench illustrated in Fig. 4;

Fig. '6 is a fragmentary plan view of a portion of a plug such as shown in Figures 1 to 3 illustrating. a slightly modified form of one detail; and

Fig, 7 is a fragmentary vertical section taken on line 1 -1, of Fig. 6.

Similar numerals refer to similar parts through the various figures in the drawing.

.Referring to Figs. 1, 2 and 3, a sheetmetal contamer is indicated generally at 6 .provided with an integral threaded: bung opening wall l and surrounded by an annular shoulder portion'8, between which threaded wall land shoulder 8 an annular gasket seat 9 is located. The bung opening construction as shown may be similarto that The present invention is not limited to plugs used in the particular bung opening construction shown, as the improved threaded sheet. metal plug may be usedin any standard pipe threaded bung opening, or may be used in anyother place where a pipe threaded plug may be desired. However, the improved threaded sheet metal plug has special advantages to be hereinafter described, when used in the particula bung opening shown.

Theimproved threaded sheet metal closure plug is indicated generally at In in Figs. .1,; 2 and 3, wherein the same is threaded into. the threaded bung opening 1. The plug ID has a closing wall H, which terminates in an integral annular wall or tubular projecting, or peripheral neck l2, which is shaped to have a zigzag formation to provide internal and external V-sided threads, the external thread 13 being a standard pipe thread. The threaded wall I 2 terminates in an integral outturned flange I4, which forms the headof the plug and clamps a liquid sealing gasket-l5 against the asket seat 9 of the container wall-to form a liquid-tight closure. 1

The flangeihead I4 terminates in an upwardly, inwardly and then downwardly curled bead or rim I6, which may be circumferentially interrupted, recessed, slotted, or notched at a plurality of places to provide for thefreception .of a tool wrench; Such notches are'indicated at IT, four notches being shown; but it is understood that any convenient number of notches may be provided, such as two, three, 'four, five or mo're notches, depending upon the diameter and size of the plug and the thicknessof sheet, metal from whichitisformed, j V U j As best shown in Fig. '3, theends lBof the c'urled bead or rim l6, which form'the sidesof the notches or recesses H, are preferably tapered or undercut, so that the upper portions thereof overhang the lower portions thereof at the bot toms I9 of the notches, and so that the slots are wider at the bottoms than atthe tops thereof.

It is to be understood" that anyavailable tool such as a screw driver, 'a bar, a" chisel, or the like may be used to engage in the notches H for screwing the plug into or unscrewing the plu from' the threaded bungopening I. However, in Figs. 3, 4 and-5, a most convenient form of plu turning wrench is illustrated, v'vhichmay comprise ahead 20 having a -ha'ndle 2| of any desired length, the underside of the head being provided with flared teeth 22 preferably formed at the lower ends of hardened steel pins inserted in the body of the head for matching with the notches I1 in the improved plug l0, whereby the plug may be readily, easily and quickly threaded into or out of the threaded bung opening I by engagement of the teeth 22 in the notches I1.

The relation of the flared teeth 22 and the curled bead or rim l6 and the notches IT on the plug I is clearly illustrated in Figures 3 and 4. As also clearly appears in Fig. 4 two circular pilot portions are formed on the head to enable the operator to readily guide the wrench centrally into the plug, an upper portion 23 to loosely enter the space within the bead and a lower portion 24 to enter the space within the threaded conformation of the plug I 0. 'An inspection of Fig. 4 will also disclose a second set of flared teeth 25 adapted to engage notches, similar to the notches H, in a somewhat smaller plug indicated generally in broken lines at 26. Upper and lower pilot portions 21 and 28, respectively, are also provided to facilitate the entrance of the teeth 25 centrally into the notches in the plug 26.

A sealing lug 29 may be welded to the barrel wall 6, and the curled plug rim It may be provided with apertures 30 so that a lead and wire seal may be connected to the sealing lug 29 and through the apertures 30 for sealing the plug in the bung opening.

Alternatively, if a tamper-proof sealing cap is desired to be used, the cap such as indicated at 3!, may enclose the plug and may be engaged at 32 over and around the barrel wall shoulder 8.

A slight modification of the conformation of the bead 15 at the sealing opening is illustrated in Figures 6 and '7, in which the inner portion of the bead I6 is notched or cut away at the sealing shaped blank between roller dies under pressure to swage, deform, cold roll, iron, burnish, spin, smooth and harden the metal wall internally and externally into zigzag thread-like formations.

After the threads have been rolled in the cupshaped blank, the flange of the blank is preferably notched in the flat, after which the outer portions of the flange which extend outwardly from a circular line passing through the base of the notches such as may be indicated by the line 35 in Fig. 2, is flanged upwardly, and finally the upwardly flanged portion is beaded or curled inwardly and downwardly to produce the finished plug shown in the drawing.

Accordingly, the curled bead or rim I6 of the improved plug in provides a smooth outer edge for the sheet metal plug, which is easy for the user to handle without injuring or cutting his hands. The curled head or rim I 6 uniformly strengthens the plug at the outer periphery of the flange [4 without materially increasing the amount of metal present in the plug, so that the plug is strongest at its beaded rim, wherein the notches are provided.

Thus, the notches I! are located on approximately the largest diameter of the plug so that maximum leverage may be applied to the plug for screwing or unscrewing the same with a tool; and the plug as just stated, is strongest at the point of application of force for tightening or loosening the same in a bung opening.

Accordingly, the improved plug has a maximum strength as related to the weight of metal used in making the same because the plug is formed ordinarily of metal having the same gauge as the metal from which the container is formed, and no excess metal is provided and cut awa for forming the threads. Moreover, only a little additional metal is used for forming the reinforcing and notched tool engaging rim Hi.

The flanged head 14 of the plug in being formed of sheet metal, has suflicient inherent springiness or resilience so as to uniformly distribute the pressure exerted by the same on the gasket l5, whereby a good liquid-tight seal is easily obtained regardless of the type of gasket used.

And finally, the plug in being formed of sheet metal preferably sheet steel, and in having the threads rolled therein, has a very smooth. thread surface which will not seize and which may be readil threaded into the threaded opening.

Accordingly, the present invention appreciably reduces the cost of the closure plugs for metallic containers, conserves metal, and only utilizes the more available type of metal such as sheet steel, The invention also provides closure plugs made of sheet metal with standard pipe threads without cutting the threads; and provides a threaded sheet metal plug which may be readily seated in liquid-tight relation in a container bung opening, and which may be readily sealed to a container in tamper-proof relation.

Having now described the features of the invention, the construction, manufacture and use combinations, constructions and devices, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

I claim:

A one piece sheet metal closure plug for containers comprising a bottom portion, an annular wall extending upward around said bottom portion, said upwardly extending annular wall being formed to zigzag shape in cross section to provide external standard V-sided pipe threads, at flange extending directly laterally and outwardly around the upper end of said annular wall in substantially acommon plane to provide a gasket seat, and a reinforcing rim around said flange, said rim extending directl upwardly from the periphery of said flange, then turned inwardly and downwardly into engagement with the body of said flange at a position a substantial distance inward from the periphery thereof, said rim having opposed downwardly diverging open ended tool engaging slots, said slots extending downwardly throughout the height of the rim to the surface of said flange, whereby a double thickness of metal is presented for engagement with an actuating tool.

' WALTER C. GROSSER. 

